This study is directed toward an analysis of the role of cyclic nucleotide-binding proteins and cyclic nucleotides in the molecular biology of posttranscriptional and translational control mechanism. Recent observations from this laboratory indicate that cyclic AMP-binding proteins of eucaryotic cells are specifically and tightly associated with RNA in 'informosome-like' ribonucleoprotein particles. The proposed research is designed to investigate the molecular basis of cyclic nucleotide-binding protein interaction with messenger RNA of reticulocytes and L-cells, in vitro. In addition, the natural relationship between cyclic nucleotide-binding proteins and messenger RNA will be examined closely in growing L-cells. A major objective of this project is to study the direct effect of cyclic nucleotide-binding proteins and the cyclic nucleotides on translation of eucaryotic messenger RNAs and messenger ribonucleoproteins. Should this investigation further support a physiological interaction of cyclic nucleotide-binding proteins and messenger RNA, it would provide a firm basis for elucidating the mode(s) of cyclic nucleotide regulatory action in eucaryotic cells.